1. Field of the Invention
The present invention relates generally to quick connect couplings and, more particularly, to a bayonet-type connector providing for stable compression of a hermetic seal therein.
2. Description of the Related Art
U.S. Pat. No. 2,818,279 of Knapp discloses a lugged pipe coupling with positive lock means. The device of Knapp is a bayonet-type coupler having a compression spring biasing apart two slidable portions, and a manually operable locking collar. Knapp does not disclose added rigidity against lateral forces applied to the coupling arrangement. In addition, Knapp does not disclose the dual threaded portion of the present invention by way of the threaded collar of a coupling ring and the projecting threaded flange for retaining the coupling nut support element as are provided in embodiments of the present invention.
In brief, particular arrangements of the present invention comprise a bayonet-type connector having a seal locking arrangement which provides a stable and secure seal that resists deformation under lateral forces. An internally threaded coupling nut support element is employed in the connector assembly to be threaded onto a coupling ring in order to secure the two parts of the connector together and maintain the gasket seal under stable compression. This more rigid configuration resists deformation by lateral forces which might otherwise breach the conventional gasket seal.
One part of the connector is a coupling ring having three internal, inwardly directed pins equally spaced about the central bore. In conventional bayonet coupler fashion, these pins slide into three spiral cam surfaces in the other connector part as the two parts are rotated relative to each other, thereby drawing the connector parts together. The pins become seated in recesses at the ends of the cam slots to provide engagement of the bayonet coupler until forcibly released.
The part of the connector with which the coupling ring is associated has an outwardly projecting shoulder extending about the shell portion at its rearward end. The coupling nut support element has a radially inwardly directed shoulder portion which bears against the shoulder portion of the shell and, when the coupling nut support element is threaded onto the coupling ring, the two interfering shoulders develop an axially directed force which increases the compression of the seal gasket beyond the extent which is developed by the standard bayonet coupling arrangement. Tightening of the support element on the coupling ring also makes the overall assembly more rigid, thereby serving to protect the bayonet coupler against lateral deformation.
The rearward portion of the coupling ring and the outwardly projecting shoulder portion of the shell are both threaded to match the internal thread of the coupling nut support element. As a result, when the coupling nut support element is unthreaded from the coupling ring, as when the bayonet coupler is disconnected, it can be removed from the associated connector portion by unthreading it to move past the outwardly projecting shoulder of the shell portion. Conversely, the forward part of the coupling nut support element is able to move into operative position by threading the part past the projecting shoulder in the opposite direction during assembly.